Messages in this thread | | | Subject | Re: [PATCH v2] iommu/arm-smmu: fix null-pointer dereference in arm_smmu_add_device | From | David Daney <> | Date | Wed, 9 Aug 2017 14:41:52 -0700 |
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On 08/08/2017 04:21 AM, Will Deacon wrote: > [+ Joerg] > > On Tue, Aug 08, 2017 at 11:37:40AM +0100, Robin Murphy wrote: >> On 08/08/17 11:26, Artem Savkov wrote: >>> Commit c54451a "iommu/arm-smmu: Fix the error path in arm_smmu_add_device" >>> removed fwspec assignment in legacy_binding path as redundant which is >>> wrong. It needs to be updated after fwspec initialisation in >>> arm_smmu_register_legacy_master() as it is dereferenced later. Without >>> this there is a NULL-pointer dereference panic during boot on some hosts. >> >> Reviewed-by: Robin Murphy <robin.murphy@arm.com> >> >> Thanks for fixing it up, and sorry for failing to document the >> unfortunately subtle logic in the first place! > > Well, I was the one that messed it up: > > Acked-by: Will Deacon <will.deacon@arm.com> > > Joerg, can you pick this up as a fix for 4.13, please?
I hit the Oops as well. This patch fixes it for me on a Cavium CN88xx system, so:
Acked-by: David Daney <david.daney@cavium.com>
Thanks for working on this.
> > Will > >>> Signed-off-by: Artem Savkov <asavkov@redhat.com> >>> --- >>> drivers/iommu/arm-smmu.c | 7 +++++++ >>> 1 file changed, 7 insertions(+) >>> >>> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c >>> index b97188a..2d80fa8 100644 >>> --- a/drivers/iommu/arm-smmu.c >>> +++ b/drivers/iommu/arm-smmu.c >>> @@ -1519,6 +1519,13 @@ static int arm_smmu_add_device(struct device *dev) >>> >>> if (using_legacy_binding) { >>> ret = arm_smmu_register_legacy_master(dev, &smmu); >>> + >>> + /* >>> + * If dev->iommu_fwspec is initally NULL, arm_smmu_register_legacy_master() >>> + * will allocate/initialise a new one. Thus we need to update fwspec for >>> + * later use. >>> + */ >>> + fwspec = dev->iommu_fwspec; >>> if (ret) >>> goto out_free; >>> } else if (fwspec && fwspec->ops == &arm_smmu_ops) { >>> >> > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
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